 |
Claims  |
|
|
What is claimed is:
1. A temperature control system for a cutaneous gas sensor having a
temperature sensing element for producing an output signal indicative of
the actual temperature of the sensor, and a heating element, comprising:
(a) a closed loop temperature control circuit for controlling the flow of
current through the heating element in accordance with the difference
between the output signal of the sensing element and a temperature
setpoint signal indicative of a desired temperature of the sensor,
(b) a switching means responsive to a disable signal for interrupting the
flow of current through the heating element,
(c) a first temperature monitoring means connected to the sensing element
for applying a disable signal to the switching means when the output of
the sensing element indicates that the temperature of the sensor has
exceeded a first predetermined value,
(d) a programmable control means connected to the sensing element, the
switching means and the temperature control circuit, said programmable
control means serving as a temperature setting means for generating said
temperature setpoint signal, and as a second temperature monitoring means
for applying a disable signal to the switching means when the output
signal of the sensing element indicates that the temperature of the sensor
has exceeded a second predetermined value, and
(e) a failure detecting means connected to the programmable control means
for applying a disable signal to the switching means when the programable
control means fails to operate in the intended manner.
2. The system of claim 1 in which the first monitoring means includes
comparing means for comparing the output signal of the sensing element to
an overtemperature reference signal, and for applying a disable signal to
the switching means when the output signal of the sensing element exceeds
the overtemperature reference signal.
3. The system of claim 2 including latching means for latching the disable
signal produced by the comparing means when the output signal of the
sensing element exceeds the overtemperature reference signal for more than
a predetermined time.
4. The system of claim 3 including means for connecting the programmable
control means to the latching means to initialize the same during the
start up of the system.
5. The system of claim 4 in which the first predetermined temperature value
exceeds the second predetermined temperature value.
6. The system of claim 1 in which the detecting means includes a resettable
means for generating a disable signal unless the programmable control
means periodically resets the same.
7. The sensor of claim 1 in which the sensor includes a second sensing
element connected to the first temperature monitoring means, and in which
said monitoring means is arranged to apply a disable signal to the
switching means when either sensing element indicates that the temperature
of the sensor has exceeded said first predetermined value.
8. The system of claim 7 in which the second sensing element is connected
to the programmable control means, and in which the programmable control
means is programmed to generate a disable signal when either sensing
element indicates that the temperature of the sensor has exceeded said
second predetermined value.
9. The system of claim 8 in which the programmable control means is
programmed to generate a disable signal when the average temperature
indicated by the sensing elements differs from the desired temperature by
more than a predetermined amount.
10. The system of claim 8 in which the programmable control means is
programmed to generate a disable signal when the temperatures indicated by
the sensing elements differ from one another by more than a predetermined
amount.
11. The system of claim 7 in which the second sensing element is connected
to the programmable control means, and in which the programmable control
means is programmed to carry out at least one temperature test which is
based on the temperature indicated by both sensing elements and to apply a
disable signal to the switching means if any such test is failed.
12. The system of claim 11 in which the programmable control means is
programmed to establish a test disable period following each change in the
temperature setpoint signal, and to not apply any disable signal to the
switching means if any of said temperature tests are failed only during
said test disable period.
13. The system of claim 12 in which the programmable control means is
programmed to store time periods for use in applying respective
temperature tests, and to determine that a temperature test has been
failed only if the failure continues after the elapse of the respective
time period.
14. A temperature control system for a cutaneous gas sensor having a first
and a second temperature sensing element for producing an output signal
indicative of the actual temperature of the sensor, and a heating element,
comprising:
(a) a closed loop temperature control circuit for controlling the flow of
current through the heating element in accordance with the output signal
of the first sensing element and a temperature setpoint signal indicative
of a desired temperature of the sensor,
(b) a switching means for controlling the flow of current through the
heating element, said switching means having an enabled state in which
current can flow through the heating element and a disabled state in which
no appreciable current can flow through the heating element,
(c) a means for applying a temperature setpoint signal to the temperature
control circuit,
(d) a first temperature monitoring means connected to the first and second
sensing elements for generating an output signal which establishes the
disabled state of the switching means when the temperature indicated by
either the first or second sensing element exceeds a first predetermined
maximum temperature,
(e) a second temperature monitoring means connected to the first and second
sensing elements for generating an output signal which establishes the
disabled state of the switching means when the difference between the
temperatures indicated by the first and second sensing elements exceeds a
predetermined value,
(f) a first and a second latching means for latching the output signals of
the first and second temperature monitoring means, and thereby maintaining
the disabled state of the switching means, and
(g) a means for preventing at least one of the monitoring means from
generating its output signal for a predetermined time after the start up
of the system.
15. A temperature control system for a cutaneous gas sensor having first
and second temperature sensing elements for producing output signals
indicative of the temperature of the sensor, and a heating element,
comprising:
(a) a closed loop temperature control circuit for controlling the flow of
current through the heating element in accordance with the output signal
of one of the sensing elements and a temperature setpoint signal
indicative of a desired temperature of the sensor,
(b) a temperature setting means for applying a temperature setpoint signal
to the temperature control circuit,
(c) a switching means for controlling the flow of current through the
heating element,
(d) a first temperature monitoring means connected to the temperature
sensing elements for turning off the switching means when the output
signal of either sensing element indicates an unacceptable temperature
condition in the sensor, wherein the presence of an unacceptable
temperature in the sensor is determined when the output signal of either
sensing element exceeds a first predetermined value,
(e) a second temperature monitoring means connected to the temperature
sensing elements for turning off the switching means when the output
signal of either sensing element indicates an unacceptable temperature
condition in the sensor, wherein the presence of an unacceptable
temperature in the sensor is deterred when the output signal of either
sensing element exceeds a second predetermined value, and
(f) a means for preventing at least one of the monitoring means from
turning off the switching means for predetermined times after the start up
of the system and after changes in the temperature setpoint signal.
16. A temperature control system for a cutaneous gas sensor having a
temperature sensing element for producing an output signal indicative of
the actual temperature of the sensor, and a heating element, comprising:
(a) a closed loop temperature control circuit for controlling the flow of
current through the heating element in accordance withthe difference
between the output signal of the sensing element and a temperature
setpoint signal indicative of a desired temperature of the sensor,
(b) a switching means responsive to a disable signal for interrupting the
flow of current through the heating element,
(c) a first temperature monitoring means connected to the sensing element
for applying a disable signal to the switching means when the output of
the sensing element indicates that the temperature of the sensor has
exceeded a first predetermined value,
(d) a programmable control means connected to the sensing element, the
switching means and the temperature control circuit, said programmable
control means serving as a temperature setting means for generating said
temperature setpoint signal, and as a second temperature monitoring means
for applying a disable signal to the switching means when the output
signal of the sensing element indicates that the temperature of the sensor
has exceeded a second predetermined value, and
(e) a storing means for storing the temperature setpont signal, and a means
for connecting the storing means between the programmable control means
and the temperature control circuit whereby the control system may
continue to maintain the sensor at the desired temperature in the event of
a malfunction in the programmable control means.
17. A temperature control system for a cutaneous gas sensor having a
temperature sensing element for producing an output signal indicative of
the actual temperature of the sensor, and a heating element, comprising:
(a) a closed loop temperature control circuit for controlling the flow of
current through the heating element in accordance with the difference
between the output signal of the sensing element and a temperature
setpoint signal indicative of a desired temperature of the sensor,
(b) a switching means responsive to a disable signal for interrupting the
flow of current through the heating element,
(c) a first temperature monitoring means connected to the sensing element
for applying a disable signal to the switching means when the output of
the sensing element indicates that the temperature of the sensor has
exceeded a first predetermined value, and
(d) a programmable control means connected to the sensing element, the
switching means and the temperature control circuit, said programmable
control means serving as a temperature setting means for generating said
temperature setpoint signal, and as a second temperature monitoring means
wherein the programmable control means is programmed to apply a reduced
temperature setpoint signal to the temperature control circuit when the
output signal of the sensing element indicates that the temperature of the
sensor has exceeded a second predetermined value.
18. A temperature control system for a cutaneous gas sensor having a
temperature sensing element for producing an output signal indicative of
the actual temperature of the sensor, and a heating element, comprising:
a closed loop temperature control circuit for controlling the flow of
current through the heating element in accordance with the difference
between the output signal of the sensing element and a temperature
setpoint signal indicative of a desired temperature of the sensor, wherein
the temperature control circuit includes a variable conducting transistor
connected in series with the heating element, and a current limitng
network for reducing conduction through the variable conducting transistor
when the current through the heating element rises above a set value,
(b) a switching means responsive to a disable signal for interrupting the
flow of current through the heating element,
(c) a first temperature monitoring means connected to the sensing element
for applying a disable signal to the switching means when the output of
the sensing element indicates that the temperature of the sensor has
exceeded a first predetermined value, and
(d) a programmable control means connected to the sensing element, the
switching means and the temperature control circuit, said programmable
control means serving as a temperature setting means for generating said
temperature setpoint signal, and as a second temperature monitoring means
for applying a disable signal to the switching means when the output
signal of the sensing element indicates that the temperature of the sensor
has exceeded a second predetermined value.
19. A temperature control system for a cutaneous gas sensor having a first
and a second temperature sensing element for producing an output signal
indicative of the actual temperature of the sensor, and a heating element,
comprising:
(a) a closed loop temperature control circuit for controlling the flow of
current through the heating element in accordance with the output signal
of the first sensing element and a temperature setpoint signal indicative
of a desired temperature of the sensor,
(b) a switching means for controlling the flow of current through the
heating element, said switching means having an enabled state in which
current can flow through the heating element and a disabled state in which
no appreciable current can flow through the heating element,
(c) a means for applying a temperature setpoint signal to the temperature
control circuit,
(d) a first temperature monitoring means connected to the first and second
sensing elements for generating an output signal which establishes the
disabled state of the switching means when the temperature indicated by
either the first o second sensing element exceeds a first predetermined
maximum temperature,
(e) a second temperature monitoring means connected to the first and second
sensing elements for generating an output signal which establishes the
disabled state of the switching means when the average temperature
indicated by the sensing elements differs from the desired temperature by
more than a predetermined amount,
(f) a first and a second latching means for latching the output signals of
the first and second temperature monitoring means, and thereby maintaining
the disabled state of the switching means, and
(g) a means for preventing at least one of the monitoring means from
generating its output signal for a predetermined time after the start up
of the system.
20. A temperature control system for a cutaneous gas sensor having a
temperature sensing element for producing an output signal indicative of
the actual temperature of the sensor, and a heating element, comprising:
(a) a closed loop temperature control circuit for controlling the flow of
current through the heating element in accordance with the output signal
of the sensing element and a temperature setpoint signal indicative of a
desired temperature of the sensor,
(b) a switching means for controlling the flow of current through the
heating element, said switching means having an enabled state in which
current can flow through the heating element and a disabled state in which
no appreciable current can flow through the heating element,
(c) a digital computer programmed to apply a temperature setpoint signal to
the temperature control circuit,
(d) a first temperature monitoring means connected to the sensing element
for generating an output signal which establishes the disabled state of
the switching means when the temperature indicated by the sensing element
exceeds a first predetermined maximum temperature,
(e) a second temperature monitoring means connected to the sensing element
for generating an output signal which establishes the disabled state of
the switching means when the temperature indicated by the sensing element
exceeds a second predetermined maximum temperature,
(f) a first and a second latching means for latching the output signals of
the first and second temperature monitoring means, and thereby maintaining
the disabled state of the switching means,
(g) a means for preventing at least one of the monitoring means from
generating its output signal for a predetermined time after the start up
of the system, and
(h) a failure detecting means connected to the computer for establishing
the disabled state of the switching means when the computer malfunctions.
21. The system of claim 20 in which the failure detecting means comprises
resettable switching means for establishing the disabled state of the
switching means unless the computer periodically resets the same.
22. A temperature control system for a cutaneous gas sensor having a
temperature sensing element for producing an output signal indicative of
the actual temperature of the sensor, and a heating element, comprising:
(a) a closed loop temperature control circuit for controlling the flow of
current through the heating element in accordance with the output signal
of the sensing element and a temperature setpoint signal indicative of a
desired temperature of the sensor,
(b) a switching means for controlling the flow of current through the
heating element, said switching means having an enabled state in which
current can flow through the heating element and a disabled state in which
no appreciable current can flow through the heating element,
(c) a first temperature monitoring means connected to the sensing element
for generating an output signal which establishes the disabled state of
the switching means when the temperature indicated by the sensing element
exceeds a first predetermined maximum temperature,
(d) a second temperature monitoring means connected to the sensing element
for generating an output signal which establishes the disabled state of
the switching means when the temperature indicated by the sensing element
exceeds a second predetermined maximum temperature,
(e) a digital computer programmed to apply a temperature setpoint signal to
the temperature control circuit, wherein the temperature setpoint signal
is reduced when at least one of the monitoring means produces its output
signal,
(f) a first and a second latching means for latching the output signals of
the first and second temperature monitoring means, and thereby maintaining
the disabled state of the switching means, and
(g) a means for preventing at least one of the monitoring means from
generating its output signal for a predetermined time after the start up
of the system.
23. A temperature control system for a cutaneous gas sensor having a first
and a second temperature sensing element for producing an output signal
indicative of the actual temperature of the sensor, and a heating element,
comprising:
(a) a closed loop temperature control circuit for controlling the flow of
current through the heating element in accordance with the output signal
of the sensing element and a temperature setpoint signal indicative of a
desired temperature of the sensor,
(b) a switching means for controlling the flow of current through the
heating element, said switching means having an enabled state in which
current can flow through the heating element and a disabled state in which
no appreciable current can flow through the heating element,
(c) a means for applying a temperature setpoint signal to the temperature
control circuit,
(d) a first temperature monitoring means connected to the first and second
sensing elements for generating an output signal which establishes the
disabled state of the switching means when the temperature indicated by
either the first or second sensing element exceeds a first predetermined
maximum temperature,
(e) a second temperature monitoring means connected to the first and second
sensing elements for generating an output signal which establishes the
disabled state of the switching means when the temperature indicated by
either the first or second sensing element exceeds a second predetermined
maximum temperature,
(f) first and second latching means for latching the output signals of the
first and second temperature monitoring means, and thereby maintaining the
disabled state of the switching means,
(g) means for preventing at least one of the monitoring means from
generating its output signal for a predetermined time after the start up
of the system,
(h) a plurality of comparators for comparing the output signals of the
first and second sensing elements to an overtemperature reference signal,
(i) a means for connecting the first latching means between the comparators
with the switching means, and
(j) a means for bypassing the first latching means.
24. A temperature control system for a cutaneous gas sensor having a
temperature sensing element for producing an output signal indicative of
the actual temperature of the sensor, and a heating element, comprising:
(a) a closed loop temperature control circuit for controlling the flow of
current through the heating element in accordance with the output signal
of the sensing element and a temperature setpoint signal indicative of a
desired temperature of the sensor, wherein the temperature control circuit
includes a variable conducting transistor connected in series with the
heating element, and a current limiting network for reducing conduction
through the variable conducting transistor when the current through the
heating element exceeds a preset value,
(b) a switching means for controlling the flow of current through the
heating element, said switching means having an enabled state in which
current can flow through the heating element and a disabled state in which
no appreciable current can flow through the heating element,
(c) a means for applying a temperature setpoint signal to the temperature
control circuit,
(d) a first temperature monitoring means connected to the sensing element
for generating an output signal which establishes the disabled state of
the switching means when the temperature indicated by the sensing element
exceeds a first predetermined maximum temperature,
(e) a second temperature monitoring means connected to the sensing element
for generating an output signal which establishes the disabled state of
the switching means when the temperature indicated by the sensing element
exceeds a second predetermined maximum temperature,
(f) a first and a second latching means for latching the output signals of
the first and second temperature monitoring means, and thereby maintaining
the disabled state of the switching means, and
(g) a means for preventing at least one of the monitoring means from
generating its output signal for a predetermined time after the start up
of the system.
25. A temperature control system for a cutaneous gas sensor having first
and second temperature sensing elements for producing output signals
indicative of the temperature of the sensor, and a heating element,
comprising:
(a) a closed loop temperature control circuit for controlling the flow of
current through the heating element in accordance with the output signal
of one of the sensing elements and a temperature setpoint signal
indicative of a desired temperature of the sensor,
(b) a temperature setting means for applying a temperature setpoint signal
to the temperature control circuit,
(c) a switching means for controlling the flow of current through the
heating element,
(d) a first temperature monitoring means connected to the temperature
sensing elements for turning off the switching means when the output
signal of either sensing element indicates an unacceptable temperature
condition in the sensor,
(e) a second temperature monitoring means connected to the temperature
sensing elements for turning off the switching means when the output
signal of either sensing element indicates an unacceptable temperature
condition in the sensor, wherein the second temperature monitoring means
includes means for carrying out a plurality of temperature tests for
determining whether acceptable temperature conditions exist within the
sensor, said tests based on the output of both of the sensing elements,
wherein one of said test comprises a determination of whether the
difference between the temperatures indicated by the sensing elements
exceeds a predetermined value, and
(f) a means for preventing at least one of the monitoring means from
turning off the switching means for predetermined times after the start up
of the system and after changes in the temperature setpoint signal.
26. A temperature control system for a cutaneous gas sensor having first
and second temperature sensing elements for producing output signals
indicative of the temperature of the sensor, and a heating element,
comprising:
(a) a closed loop temperature control circuit for controlling the flow of
current through the heating element in accordance with the output signal
of one of the sensing elements and a temperature setpoint signal
indicative of a desired temperature of the sensor,
(b) a temperature setting means for applying a temperature setpoint signal
to the temperature control circuit,
(c) a switching means for controlling the flow of current through the
heating element,
(d) a first temperature monitoring means connected to the temperature
sensing elements for turning off the switching means when the output
signal of either sensing element indicates an unacceptable temperatures
condition in the sensor,
(e) a second temperature monitoring means connected to the temperature
sensing elements for turning off the switching means when the output
signal of either sensing element indicates an unacceptable temperature
condition in the sensor, wherein the second temperature monitoring means
includes means for carrying out a plurality of temperatures tests for
determining whether acceptable temperature condition exist within the
sensor, said tests based on the output of both of the sensing elements,
wherein one of said test comprises a determination of whether the average
of the temperatures indicated by the sensing elements is within a
predetermined range of temperature, and
(f) a means for preventing at least one of the monitoring means from
turning off the switching means for predetermined times after the start up
of the system and after changes in the temperature setpoint signal.
27. The system of claim 26 in which another of said temperatures tests
comprises a determination of whether the difference between the
temperatures indicated by the sensing elements exceeds a predetermined
value.
28. A temperature control system for a cutaneous gas sensor having first
and second temperature sensing elements for producing output signals
indicative of the temperature of the sensor, and a heating element,
comprising:
(a) a closed loop temperature control circuit for controlling the flow of
current through the heating element in accordance with the output signal
of one of the sensing elements and a temperature setpoint signal
indicative of a desired temperature of the sensor,
(b) a temperature setting means for applying a temperature setpoint signal
to the temperature control circuit,
(c) a switching means for controlling the flow of current through the
heating element,
(d) a first temperature monitoring means connected to the temperature
sensing elements for turning off the switching means when the output
signal of either sensing element indicates an unacceptable temperature
condition in the sensor,
(e) a second temperature monitoring means connected to the temperature
sensing elements for turning off the switching means when the output
signal of either sensing element indicates an unacceptable temperature
condition in the sensor, wherein the second temperature monitoring means
includes means for carrying out a plurality of temperature tests for
determining whether acceptable temperature conditions exist within the
sensor, said tests based on the output of both of the sensing elements,
wherein the second temperature monitoring means establishes a test disable
period following a change in the temperature setpoint signal and does not
turn off the switching means if any of said tests are failed during said
test disable period, and
(f) a means for preventing at least one of the monitoring means from
turning off the switching means for predetermined times after the start up
of the system and after changes in the temperature setpoint signal. |
|
 |
|
 |
Claims |
|
